The present invention disclosed herein relates to an apparatus for generating/detecting a Terahertz (THz) wave and a method of manufacturing the same, and more particularly, to an apparatus for generating/detecting a THz wave adopting a cost-saving lens and a method of manufacturing the same.
A THz wave technology of 0.1 THz to 3 THz range in the electromagnetic band has a feature that transmits non-metallic and non-polar materials as well as a feature that resonant frequencies of very various molecules are distributed within the above range. The terahertz wave technology is a high-technology field that is expected to provide a new conceptual analysis technology that has never been in various application fields such as medicals, agricultures, foods, environment measurements, biotechnologies, safeties, and high-tech material evaluations using real-time identification of the molecules by non-destructive, non-opening, and non-contact methods. Since the terahertz wave technology has little effect on a human body due to very low energy level of several meV, the terahertz wave technology is rapidly rising as an essential core technology for realizing an anthropocentric ubiquitous society, and the demands on the terahertz wave technology are rapidly increasing.
Examples of currently-used terahertz generation methods include a frequency multiplying method, a backward wave oscillator, a photomixing, a CO2 pumped gas laser, a quantum cascade laser, and a free electron laser. Many studies are being conducted to develop a terahertz wave source operating in a frequency band of 0.1 THz to 10 THz, so-called terahertz gap, but have not yet been developed to an appropriate terahertz wave source technology meeting portable, non-cooling, and low-costing requirements necessary for commercialization.
An apparatus for generating/detecting terahertz wave most extensively used until recently employs a photomixing method based on Time Domain Spectroscopy (TDS) that generates a terahertz wave by irradiating a femtosecond ultra-short pulse laser on a semiconductor having a high-speed response time. The apparatus for generating/detecting terahertz wave including a femtosecond high power pulse laser and a photomixer has an advantage of providing a high signaltonoise ratio (SNR), but essentially requires the femtosecond high power pulse laser and a very delicate optical system. Accordingly, there are many limitations for development into a portable measuring instrument due to high price and great system size.
An apparatus for generating/detecting terahertz wave based on Frequency Domain Spectroscopy (FDS) that have been developed later than the TDS receives new attention as a more portable and commercialized technology by using two continuous wave diode lasers (LD) of cheap price and small size as an excitation light source instead of a femtosecond high-power laser of expensive price and great size. However, since using various expensive components and delicate packaging technologies, this FDS-based apparatus for generating/detecting terahertz wave is still known as an expensive apparatus used only in laboratories. Recently, various commercialization technologies such as attempts to use a dual-mode tunable LD as an excitation light source and integrate the excitation light source and a photomixer are being studied for portability and cost-saving.